Cat genetics are fascinating, especially in the case of black cats. All cats’ eye colors are determined by genetics. Cats with orange eyes will have more pigment-producing cells (AKA melanocytes) in their irises. How active these melanocytes are will determine how intense of an orange color t...
Ethologists, and others who study wolves, have suggested that the light-colored irises of wolves are adaptive. They may be useful for communication in the wild. Lighter irises make the pupils more visible. Since wolves are cooperative hunters this allows other members of the pack to...
Why do some dogs have only one blue eye? Genetic variants don’t always affect both eyes. As a result, dogs can end up with one blue eye and one eye of a different color. This trait is called heterochromia iridis, but it goes by many other names—including “odd eyes,”“split eyes...
I think one reason we percieve moonlight as softer is that at such low light levels, our irises are so wide-open that we can't really focus sharply, almost like a bad Zeiss Super-Speed wide-open. On a clear night with a full moon, look at the shadows of trees on the ground, or ...